CVE-2025-21734 misc: fastrpc: Fix copy buffer page size
A flaw in the Linux kernel fastrpc driver allows improper page size calculation, potentially leading to memory corruption and code execution.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-21734?
CVE-2025-21734 is a high-severity memory corruption vulnerability in Linux kernel, published on 27 Feb 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
misc: fastrpc: Fix copy buffer page size
For non-registered buffer, fastrpc driver copies the buffer and pass it to the remote subsystem. There is a problem with current implementation of page size calculation which is not considering the offset in the calculation. This might lead to passing of improper and out-of-bounds page size which could result in memory issue. Calculate page start and page end using the offset adjusted address instead of absolute address.
Weakness: CWE-787
Which versions are affected by CVE-2025-21734?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2025-21734?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2025-21734 being exploited?
There is no known exploitation of CVE-2025-21734 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-68970, BELL-CVE-2025-21734, DEBIAN-CVE-2025-21734, GHSA-r5rr-wmp2-hj47, ROOT-OS-DEBIAN-11-CVE-2025-21734, ROOT-OS-UBUNTU-2204-CVE-2025-21734 and 2 more.